Photographic materials are not only adversely affected by light but are also deteriorated by moisture, gas, X-ray and electrostatic force as well as by chemical substances having oxidation-reduction activity. In general, since the kind and the amount of additives contained in thermoplastic resins to be used as packaging materials have an influence on the qualities of packaged photographic materials (for example, sensitization or desensitization as well as occurrence of fog and spot), various kinds of conventional commercial polyethylene, polypropylene, polystyrene, ABS, PC, etc. may not be utilized as packaging materials for photographic materials, and therefore some kinds of special resins containing specifically defined additives of a specifically defined amount have heretofore been specifically ordered for said packaging materials. Under the circumstances, imported thermoplastic resins of low price have not heretofore been used for packaging photographic materials, because the additives used therein and the amount thereof are not identified, some factors in the preparation of said resins may possibly be changed, and such confirmation that the resins do not contain any substances harmful to photographic materials cannot be assured. In addition, although it is known that waste materials containing thermoplastic resin scraps are low-priced, these have not heretofore been utilized at all as materials for packaging photographic materials, because the contents of said waste resins are not clear at all, particularly with respect to the adsorbed oils and chemicals and the kind and amount of used additives, said resins contain an extremely large amount of harmful substances compared to conventional packaging materials for photographic materials which are generally used in this technical field, and photographic materials are extremely sensitive to said waste resins and react therewith.
On these grounds, the raw materials of thermoplastic resins to be used as packaging materials for photographic materials must be limited to only those of high quality whose characteristics are definitely clarified and which are quite free from any harmful substances, in the present situation.
Accordingly, such special resins that the kind and the amount of the additives contained therein are specifically defined according to the photographic materials to be packaged and are to be used for said purpose, and therefore the packaging materials have heretofore been extremely expensive and high-priced.
On the other hand, commercial resin raw materials, especially imported resins and reclaimed resins, are low-priced, and therefore, if these may be utilized for packaging photographic materials, the utilization is industrially advantageous.